Free open-source disk encryption software for Windows Vista/XP, Mac OS X, and Linux
Main Features:
Creates a virtual encrypted disk within a file and mounts it as a real disk.
Encrypts an entire partition or storage device such as USB flash drive or hard drive.
Encrypts a partition or drive where Windows is installed (pre-boot authentication).
Encryption is automatic, real-time (on-the-fly) and transparent.
Provides two levels of plausible deniability, in case an adversary forces you to reveal the password:
1) Hidden volume (steganography – more information may be found here).
2) No TrueCrypt volume can be identified (volumes cannot be distinguished from random data).
Encryption algorithms: AES-256, Serpent, and Twofish. Mode of operation: XTS. Further information regarding features of the software may be found in the documentation.
what's new in v5.1
5.1 March 10, 2008
New features:
Support for hibernation on computers where the system partition is encrypted (previous versions of TrueCrypt prevented the system from hibernating when the system partition was encrypted). (Windows Vista/XP/2008/2003) Ability to mount a partition that is within the key scope of system encryption without pre-boot authentication (for example, a partition located on the encrypted system drive of another operating system that is not running). (Windows Vista/XP/2008/2003)
Note: This can be useful e.g. when there is a need to back up or repair an operating system encrypted by TrueCrypt (from within another operating system). Command line options for creating new volumes. (Linux and Mac OS X) Improvements:
Increased speed of AES encryption/decryption (depending on the hardware platform, by 30-90%). (Windows) Faster booting when the system partition is encrypted. (Windows Vista/XP/2008/2003) When the system partition/drive is encrypted, the TrueCrypt Boot Loader is now stored in a compressed form and is, therefore, smaller. If a non-cascade encryption algorithm is used (i.e., AES, Serpent, or Twofish), the TrueCrypt Boot Loader is now small enough so that a backup of the TrueCrypt Boot Loader can be (and is) stored in the first drive cylinder. Whenever the TrueCrypt Boot Loader is damaged, its backup copy is run automatically instead. As a result of this improvement, the following problem will no longer occur: Certain inappropriately designed activation software (used for activation of some third-party software) writes data to the first drive cylinder, thus damaging the TrueCrypt Boot Loader. The affected users had to use the TrueCrypt Rescue Disk to repair the TrueCrypt Boot Loader. This will no longer be necessary after upgrading to this version of TrueCrypt (provided that the system partition/drive is encrypted using a non-cascade encryption algorithm, i.e., AES, Serpent, or Twofish). Note: If your system partition/drive is currently encrypted using a non-cascade encryption algorithm (i.e., AES, Serpent, or Twofish), a backup copy of the TrueCrypt Boot Loader will be automatically stored in the first drive cylinder when you upgrade to this version of TrueCrypt. The minimum memory requirements for the TrueCrypt Boot Loader have been reduced from 42 KB to 27 KB (twenty-seven kilobytes). This allows users to encrypt system partitions/drives on computers where the BIOS reserves a large amount of memory. (Windows Vista/XP/2008/2003) Many other minor improvements. (Windows, Mac OS X, and Linux) Resolved incompatibilities:
On some computers, when performing the system encryption pretest, Windows failed to display the log-on screen. This will no longer occur. (Windows Vista/XP/2008/2003) Bug fixes:
On some systems, drive letters were not correctly assigned to newly mounted non-system volumes. This will no longer occur. (Windows) Many other minor bug fixes. (Windows, Mac OS X, and Linux)
Parallelized encryption/decryption on multi-core processors (or multi-processor systems). Increase in encryption/decryption speed is directly proportional to the number of cores and/or processors.
For example, if your computer has a quad-core processor, encryption and decryption will be four times faster than on a single-core processor with equivalent specifications (likewise, it will be twice faster on dual-core processors, etc.)
[View benchmark results]
Ability to create and run an encrypted hidden operating system whose existence is impossible to prove (provided that certain guidelines are followed). For more information, see the section Hidden Operating System. (Windows Vista/XP/2008/2003)
For security reasons, when a hidden operating system is running, TrueCrypt ensures that all local unencrypted filesystems and non-hidden TrueCrypt volumes are read-only. (Data is allowed to be written to filesystems within hidden TrueCrypt volumes.)
Note: We recommend that hidden volumes are mounted only when a hidden operating system is running. For more information, see the subsection Security Precautions Pertaining to Hidden Volumes.
On Windows Vista and Windows 2008, it is now possible to encrypt an entire system drive even if it contains extended/logical partitions. (Note that this is not supported on Windows XP.)
New volume format that increases reliability, performance and expandability: Each volume created by this or later versions of TrueCrypt will contain an embedded backup header (located at the end of the volume). Note that it is impossible to mount a volume when its header is damaged (the header contains an encrypted master key). Therefore, embedded backup headers significantly reduce this risk. For more information, see the subsection Tools > Restore Volume Header.
Note: If the user fails to supply the correct password (and/or keyfiles) twice in a row when trying to mount a volume, TrueCrypt will automatically try to mount the volume using the embedded backup header (in addition to trying to mount it using the primary header) each subsequent time that the user attempts to mount the volume (until he or she clicks Cancel). If TrueCrypt fails to decrypt the primary header and then decrypts the embedded backup header successfully (with the same password and/or keyfiles), the volume is mounted and the user is warned that the volume header is damaged (and informed as to how to repair it).
The size of the volume header area has been increased to 128 KB. This will allow implementation of new features and improvements in future versions and ensures that performance will not be impaired when a TrueCrypt volume is stored on a file system or device that uses a sector size greater than 512 bytes (the start of the data area will always be aligned with the start of a host-filesystem/physical sector).
For more information about the new volume format, see the section TrueCrypt Volume Format Specification.
Note: Volumes created by previous versions of TrueCrypt can be mounted using this version of TrueCrypt. Parallelized header key derivation on multi-core processors (one algorithm per core/thread). As a result, mounting is several times faster on multi-core processors. (Windows)
Ability to create hidden volumes under Mac OS X and Linux.
On Linux, TrueCrypt now uses native kernel cryptographic services (by default) for volumes encrypted in XTS mode. This increases read/write speed in most cases. However, the FUSE driver must still be used when the volume is encrypted in a deprecated mode of operation (LRW or CBC), or when mounting an outer volume with hidden-volume protection, or when using an old version of the Linux kernel that does not support XTS mode. (Linux)
Improvements:
Up to 20% faster resuming from hibernation when the system partition/drive is encrypted. (Windows Vista/XP/2008/2003)
Many other improvements. (Windows, Mac OS X, and Linux)
Removed features:
Encrypted system partitions/drives can no longer be permanently decrypted using the TrueCrypt Boot Loader (however, it is still possible using the TrueCrypt Rescue Disk). (Windows Vista/XP/2008/2003)
Note: This was done in order to reduce the memory requirements for the TrueCrypt Boot Loader, which was necessary to enable the implementation of support for hidden operating systems.
Bug fixes:
When Windows XP was installed on a FAT16 or FAT32 partition (as opposed to an NTFS partition) and the user attempted to encrypt the system partition (or system drive), the system encryption pretest failed. This will no longer occur.
Many other minor bug fixes and security improvements (preventing e.g. denial-of-service attacks). (Windows, Mac OS X, and Linux
The ability to configure selected volumes as 'system favorite volumes'. This is useful, for example, when you have volumes that need to be mounted before system and application services start and before users start logging on. It is also useful when there are network-shared folders located on a TrueCrypt volume and you need to ensure that the network shares will be restored by the system each time it is restarted. For more information, see the chapter 'Main Program Window', section 'Program Menu', subsection 'Volumes -> Save Currently Mounted Volumes as Favorite' in the documentation. (Windows)
Improvements and bug fixes:
'Favorite' volumes residing within partitions or dynamic volumes will no longer be affected by changes in disk device numbers, which may occur, e.g., when a drive is removed or added. (Windows)
Many other minor improvements and bug fixes. (Windows, Mac OS X, and Linux)
Workaround for a bug in some custom (non-Microsoft) drivers for storage device controllers that caused a system crash when initiating hibernation on TrueCrypt-encrypted operating systems. (Windows 7/Vista/2008/2008R2)
Other minor improvements (Windows, Mac OS X, and Linux)
TrueCrypt is a software system for establishing and maintaining an on-the-fly-encrypted volume (data storage device).
Features of TrueCrypt 7.0 :
· It can create a virtual encrypted disk within a file and mount it as a real disk.
· It can encrypt an entire hard disk partition or a device, such as USB memory stick, floppy disk, etc.
· Encryption is automatic, real-time (on-the-fly) and transparent.
· Provides two levels of plausible deniability, in case an adversary forces you to reveal the password:
· Hidden volume (more information may be found here).
· No TrueCrypt volume can be identified (TrueCrypt volumes cannot be distinguished from random data).
· Encryption algorithms: AES-256, Serpent, and Twofish. Mode of operation: XTS.
